Oh! They filter better and process much more volume than I had thought. But they still don't do the job your lungs need them to do. Even with those running, I wouldn't want to work in your shop without a respirator, but that's my choice. YMMV.
I'm sure they clear the sweeping dust quickly. Don't you have a sweeper head for the DC? I love mine. It's much easier than sweeping and cleaning up. I should use it some day soon...
-- That's the thing about needs. Sometimes, when you get them met, you don't need them anymore. -- Michael Patrick King